==BSA - Bethesda Softworks Archives==
BSA files are container packages for game asset files. It is similar to a Zip archive but uses a special encryption and requires a specific tool to unpack the contents so the models, textures, animation and audio can be modified and included in game modifications.

Each model must have two textures...a diffuse and normal map. (Menu/2D items do not need normal maps)

===Diffuse texture===
The Diffuse texture is how the object is painted...it wraps around the model based on the defined [[UV Mapping: An Explanation|UV Map]] of the model. The name of the texture and its path is controlled inside the NIF file using the texture path. If the texture cannot be found using the path inside the NIF, the game may crash or the object will appear pink. There are some instances where the texture path is controlled in the plugin such as hair. To update the path, please read this tutorial: [[How to fix hard-coded texture paths in NIF files]].

If the NIF model allows for transparency ([http://cs.elderscrolls.com/constwiki/in ... erty_Nodes NiAlphaProperty]), the alpha channel of the diffuse texture will contain a grayscale image that defines the amount of transparency of the texture on the model. 100% white is solid opaque (no transparency). 100% black is completely transparent. The shades of gray in between control the amount of transparency such as 50% grey (RGB: 128,128,128) is 50% transparent.

===Normal map===
The normal map is how light reacts to the model's surface giving it the illusion of highs and lows in the geometry where there are none. The best normal maps are created using a high-poly version of a model and having the details baked onto the low-poly model. If a high-poly models is not available, the normal map must be created in other ways such as by using the diffuse texture. This can be done using Nvidia plugins for Adobe Photoshop or plugins for GIMP. A very handy tool for this is called CrazyBump. To get a better understanding of what Crazybump can do, take a look at CrazyBump's intro movie: [http://www.crazybump.com/ Creating Materials with CrazyBump]. The game engine automatically determines the name of the normal map by using the name of the diffuse texture and adding "_n" to it. Example: Helmet.dds --> Helmet_n.dds. The game can crash if the normal map does not exist...or it can render the object invisible.

More often than not, a specularity map is copied into the alpha channel of the normal map to control the shine factor of the surface. The specularity map is a grayscale image that looks very similar to the diffuse texture but is tweaked to fine tune surface effects.

It should also be noted that there is a glossiness setting in the NiMaterialProperty in the NIF file which affects how "glossy" the material appears.

There are other tricks you can utilize to make use of special materials to make uber-reflective materials...[[Reflective metal]]

===Glow map===
The glow map is optional and controls the color and intensity of the glow on the surface of the texture. The game engine automatically determines the name of the glow map (if it exists) by using the name of the diffuse texture and adding "_g" to it. Example: Helmet.dds --> Helmet_g.dds. You could make an object glow by controlling the material settings inside the NIF but that would cause the entire object to glow. Using a glow map allows you to make just certain parts glow. [[Glowmaps 101]]

==HTM - Hypertext markup language==
A text file that contains text formatted in HTML (Hypertext markup language) designed for view within a web browser such as Firefox or Internet Explorer. The file can be edited with Notepad, Notepad++, Dreamweaver or any editor that can open and save to a text file.

==KF - Animation==
KF files hold animation information that can be applied to a NIF file.

==LIP - Lip sync data==

==LOD - Level of detail==
LOD (Level of detail) refers to the use of conserving memory and cpu processing by using lower resolution (less geometry) models and/or textures on objects far away from the player. The further away the object, the smaller and less complex model and/or texture is used. These can be generated using the construction set or 3rd-party tools.

==MP3 - Music/audio==
These are typically music but can also be sound FX or voice files depending on where you find them in the folder structure. These can be opened with audio editors such as Audacity or Sound Forge. The Nexus Forums has an [http://www.thenexusforums.com/index.php ... 327-audio/ audio forum] dedicated to this subject.

==NIF - Models and skeleton bones==
NIF (NetImmerse File Format) files are special containers for models and objects in the game and are typically referred to as "mesh" files and found in the "Data\Meshes" folder structure. They contain more than just the model itself, but also the UV map, material properties, texture paths, animation sequences, animation morphs and many other game settings all releated to the 3D object.

NifSkope is the primary editor of NIF files but they can also be imported to and exported from various 3D modeling programs such as 3ds Max and Blender. The Nexus Forums has a [http://www.thenexusforums.com/index.php ... modelling/ 3D modelling forum] dedicated to this subject.